fire and 2/9th Marines suffered 7 killed and 12 wounded. On 20 May, 3rd Battalion, 9th Marines covering the left flank of the operation encountered a PAVN bunker complex and in fighting lasting into 21 May suffered 26 killed and 59 wounded for 36 PAVN dead. The reserve Special Landing Force Bravo 2nd Battalion, 3rd Marines joined the operation on 20 May landing by helicopter northwest of Firebase Gio Linh. They swept the area north to the DMZ meeting minimal resistance but discovering PAVN bunkers and supplies. On 25 May, Company H, 2/26th Marines engaged a large PAVN Company at the base of Hill 117, 5 km west of Con Thien. Company H joined by Company K, 3/4th Marines made repeated advances up the hill against the PAVN with heavy fighting lasting throughout the day and costing 14 Marines and corpsmen killed and 92 wounded, while claiming 41 PAVN were killed. Marine air and artillery pounded the top of the hill throughout the night, and a new assault was planned for the morning of 26 May, but PAVN fire brought down a UH-1E, injuring the command element, and the assault was postponed until 27 May when Companies E and F, 2/26th Marines and 3/4th Marines secured the hilltop with no resistance. For the remainder of Operation Hickory the Marines encountered only scattered resistance but discovered and destroyed numerous bunkers, ordnance and rice. Operation Hickory concluded on 28 May; the Marines had suffered 142 KIA and 896 wounded with US claims of 362 PAVN killed. Lam Son 54, Hickory, Belt Tight and Beau Charger also resulted in the removal of the entire civilian population from the area with the result that it was all now a free fire zone. Operation Prairie IV At the conclusion of Operation Hickory, all participating units joined Operation Prairie IV sweeping the area southwest of Con Thien. On 28 May 3/4 Marines ran into a bunker complex on Hill 174, 6 km southwest of Con Thien. Companies M and L attacked the complex but were forced back by small arms, machine guns, 57mm recoilless rifle and 82mm mortars for the loss of 2 Marines killed and 21 wounded. Artillery hit the hill throughout the night and the next day Companies M and I attacked the hill, suffering 5 KIA and 33 wounded without driving the PAVN from the crest of the hill. Companies M and I